Question

Comercially available sulphuric acid contain 93% acid by mass and has the density 1.84gmol/L. Calculate molarity?

Answer 1

In 100g of 93% solution,

Mass of sulfuric acid= 93g

molar mass of of sulfuric acid= 98g

number of moles in 93g of sulfuric acid= 93/98 = 0.94 moles

density of sulfuric acid = 1.84 g/ml

Volume of 93 g sulfuric acid= mass / density

= 93/1.84

=50.54 ml

Mass of water in 93% solution = 7 g

molar mass of water =18g

number of moles of water =7/18 =0.388 g

density of water = 1g/ml

volume of 7g water = 7ml

total volume of the solution

= 50.54+7 =57.54ml

molarity = number of moles of solute x1000/ volume of solution in ml

= 0.94 x 1000/57.54

=16.33